Automatic leveling device



P 27, 1966 J. H KONEFES AUTOMATIC LEVELING DEVICE 2 Sheets-Sheet 1 Filed June 7, 1965 INVENTOR JOSEPH H. KONEFES BY WWW,

ATTY.

Sept. 27, 1966 J. H. KONEFES AUTOMATIC LEVELING DEVICE 2 Sheets-Sheet 2 Filed June 7. 1965 INVENTOR JOSEPH H. KONEFES BY WXW,

ATTY.

United States Patent 3,275,174 AUTOMATIC LEVELING DEVICE,

Joseph H. Konefes, Libertyville, Ill., assignor to International Harvester Company, a corporation of Delaware Filed June 7, 1965, Ser. No. 461,866 1 Claim. (Cl. 214-761) This invention relates to a leveling device for a material handling bucket and more particularly relates to an automatic leveling device for a material handling bucket for use in combination with a bucket position indicator on a construction vehicle.

It is an object of this invention to provide an automatic leveling device which operates responsive to the position of a material handling bucket to terminate movement of a hydraulic ram which actuates the bucket.

It is another object of this invention to provide an automatic leveling device for a material handling bucket in which a sheave-drum assembly is utilized as a bucket position indicator whereby movement of the drum to indicate the level position of the bucket will terminate operation of the ram which positions the bucket.

Another object of this invention is to provide an automatic leveling device for use with a material handling bucket in which a sheave-drum assembly indicates the level, carry, or dump positions of the bucket and in which a camming surface on the assembly actuates means to terminate movement of the bucket when the bucket is in the level position.

The foregoing and other objects are realized in accordance with the present invention by providing an air actuated piston which operates in response to movement of a sheave-drum indicator assembly as it indicates the level position of a material handling bucket. The piston operates to release a detent mechanism which holds the spool of a hydraulic control valve in an operating position for directing fluid to a bucket tilting ram. Upon release of the detent the spool will return to the neutral position whereby operation of the ram is terminated and the bucket will remain in the level position until fiurther manipulation of the control valve by the operator.

The invention, both as to its organization and method of operation, taken with further objects and advantages thereof, will best be understood by reference to the following description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevation view of a tractor loader incorporating an automatic bucket leveling device embodying features of the present invention;

FIGURE 2 is an enlarged top plan view of component units of the present invention;

FIGURE 3 is a side elevational view of a component unit of the invent-ion taken along the line 3-3 of FIG- URE 2 in which the unit is mounted on the bucket tilting ram of the tractor loader of FIGURE 1; and

FIGURE 4 is a greatly enlarged cross-sectional view of component parts of the hydraulic control valve and detent mechanism as utilized in the present invention Referring now to the drawings, and particularly to FIGURE 1, the reference numeral indicates generally a front end tractor loader. A pair of boom arms 12 are pivotally mounted on the tractor loader 10 and a pair of extensible hydraulic rams 14 are provided to raise and lower the boom arms. A material handling bucket 16 is mounted on the free ends of the boom arms by means of pins 18 for pivotal movement about a transversely extending axis.

Pivotal movement of the bucket 16 relative to the boom arms is effected by means of an extensible hydraulic ram 20 and a rocker arm lever 22. The ram 20 is pivotally connected at its head end to the tractor loader 10 by means of pivot pin 24, and is pivotally connected at its rod end 70 to the upwardly extending portion of rocker arm lever 22 by means of pin 26. The rocker arm lever 22 is pivotally connected intermediate its ends between the pair of boom arms 12 by means of pivot pin 28. A link 30 is pivotally connected at one end to the lowermost end of the rocker arm lever by means of pin 32 and at its other end to the bucket 16 by means of pin 34.

Extension of hydraulic ram 20 through operation of hydraulic control valve 36 will pivot the bucket 16 backward with respect to the boom arms 12 about pivot pins 18; retraction of the ram 20 will pivot the bucket 16 forward with respect to the boom arms 12.

The hydraulic control valve 36 is positioned within the cab of tractor loader 10 so that its associated control lever 38 is within easy reach of the operator. The control valve 36 is broadly conventional and details of its construction will be well known to those skilled in the art. Suflflce it to say that manipulation of the control lever 38 operates to direct hydraulic fluid from a source of fluid pressure (not shown) through hydraulic conduits (not shown) for selective extension and retraction of ram 20. The control valve 36 has a spool 40 (FIG- URE 4) which is movable from a neutral position to first and second operating positions upon manipulation of the control lever 38. When the control lever 38 is manipulated to move the spool 40 to the left of the neutral position fluid under pressure will be directed to the rod end of ram 20 to retract the ram and dump the bucket 16 forwardly. When the control lever 38 is manipulated to move the spool 40 to the right of the neutral position, the control valve 36 will direct fluid under pressure to the head end of ram 20 to extend the ram and pivot the bucket 16 backwards to the level and carry positions.

A bucket position indicator 42 is mounted on the upper side of the head end of the ram 20 within the range of vision of the operator. FIGURES 2 and 3 show details of the bucket position indicator 42. A flat mounting bracket 44 is secured to the head end of the ram 20 by means of pins 46. A spindle 48 is rigidly secured to the forward end of the bracket 44 and extends in an upward direction from the ram 20. A sheave-drum assembly 50 is rotatably mounted on the distal end of spindle 48. The assembly 50 comprises cover member 52 rotatably mounted on spindle 48, a drum 54 coaxial with and radially spaced from spindle 48, and a pair of spacedapart disks 56 and 58 secured to the drum 54 to define a sheave therewith. A coil spring 60 is mounted around the spindle 4'8 and is secured at its one end to bracket 44 and at its other end to cover member 52. The spring 60 urges the assembly 50 to rotate in the counterclockwise direction as viewed in FIGURE 2. A length of cable 62 is secured at one end to the sheave-drum assembly 50 and is partially wound between the disks 56 and 58. The cable is threaded through the eye of guide member 64 which in turn is secured to flange 66 of ram 20. The end of cable 62 is secured to a bracket 68 which in turn is secured to the rod end 70 of the ram 20. Appropriate indicia such as Level, Dump, and Carry are provided on the outer surface of cover member 52 to indicate the bucket position. A pointer member 72 is secured to the bracket 44 and extends upwardly in juxtaposition to the indicia on the cover member 52.

As the ram 20 is retracted so that bucket 16 is dumped forward coil spring 60 will rotate the sheave-drum assembly 50 counterclockwise, thus winding the cable 62 on the sheave. The assembly 50 will rotate until the indicia Dump is aligned with the pointer member 72. Upon extension of the ram 20 to pivot the bucket 16 backwards to the level and carry positions, the cable 62 will move outward and unwind from the sheave-drum assembly 50 which will'rotate in a clockwise direction. The indicia Level and Carry respectively will then move into alignment with the pointer member 72.

After the operator has dumped the material from the bucket 16 and has operated the control lever 38 to direct fluid to extend ram 20 and return the bucket to the level position, it is desirable that means be provided to automatically terminate opera-tion of control valve 36 when bucket 16 reaches the level position. This will enable the operator to independently operate the controls to lower the boom arms and maneuver the tractor loader 10 into the next loading position. T provide this feature a detent mechanism 74 (FIGURE 4) is mounted adjacent the control valve 36. The mechanism 74 includes a tubular housing 76 which encloses the end of spool 40 projecting outwardly from the valve 36. A pair of centering sleeves 78 are slidably mounted within the annular space between the spool 40 and the inner surface of housing 76. A compression spring 80 resiliently urges the sleeves apart. The sleeves 78 are in contact with shoulders on spool 40 and urge the spool to the neutral position from either of the first or second operating positions. A tubular extension 82 is formed on the end of spool 40 and has a pair of apertures 86 formed in its outer margin. A ball or detent 84 is positioned in each of the apertures 86. A plunger 88 is slidably mounted within the tubular extension 82 and is resiliently urged toward the detents by means of a coil spring 90. A camming surface 92 is formed at the free end of plunger 88 and operates to urge the detents 84 outwardly through the apertures 86. An end member 94 is secured to the outermost end of housing 76 and has an annular groove 96 formed within its inner surface. With the spool 40 moved to the right, as indicated by the broken-line position 97 in FIGURE 4, the detents 84 will be cammed outwardly into the groove 96. The detents will hold the extension 82 and spool 40 against the force of spring 80 andthus the control valve 36 will continue to operate to extend ram 20 until the holding force of the detents is overcome and the spool is returned to the neutral position.

The operator may override the detents by merely manipulating control lever 38 so that spool 40 is moved to the left to urge the detents out of the annular groove 96. The spool 40 is also automatically returned to the neutral position when the bucket 16 reaches its level position by means responsive to rotation of the bucket position indicator 42 to the level position. This means is illustrated in FIGURES 2 and 3 and includes a camming surface 98 which is rigidly secured to the disk 58 on the sheave-drum assembly 50. An air control valve 100 is rigidly secured to the bracket 44 in juxtaposition to the camming surface 98. The air control valve 100 includes an air supply conduit 102 which receives air under pressure from a pump (not shown), and an air conduit 104 which delivers air under pressure to the detent mechanism 74 upon operation of the air valve 100. A cam follower 106 is pivotally mounted on the air valve 100 and is in operating contact with the camning surface 98. The cam follower 106 will operate valve 100 to provide open communication from conduit 102 into conduit 104 when the sheave-drum assembly 50 is rotated to the Level position as shown in FIG- URE 2.

g A cylinder 108 is provided in the end member 94 and is in open communication with the air conduit 104. A captive piston 110 is slidably mounted Within the cylinder 108 and has an inwardly extending projection 112. Air pressure in cylinder 108 will operate to move piston 110 so that projection 112 will contact the end of plunger 88.

This will provide sufficient force to release camming surface 92'from detents 84, thus allowing said detents to move out of the annular groove 96 so that the compression spring and sleeve 78 will return spool 40 to the neutral position.

In operation, assuming that the'operator has filled the bucket and elevated the boom arms to the desired dumping height, the control lever 38 is manipulated to move the spool 40 to the lefthand position so that control valve 38 will direct fluid to retract ram 20. The ram 20 will operate rocker arm linkage 22 to pivot bucket 16 forwardly to dump the load. Concurrently with this the indicator 42 will rotate to indicate the Dump position. Cam 98 will be out of contact with cam follower 106, thereby shutting off air pressure in air conduit 104. The operator will now manipulate control lever 38 so that spool 40 is moved to the righthand position indicated by the broken-line position 97 in FIGURE 4. Detents 84 will be seated in groove 96 to hold spool 40 in this position. The hydraulic control valve 36 will now operate to extend ram 20 so that rocker arm linkage 22 will pivot bucket 16 backwards toward the level position. At this time the operator is free to manipulate the boom arm control valve (not shown) to lower the boom into a digging position. As the ram 20 is extended the sheavedrum assembly 50 will rotate clockwise and carry the cam 98 into contact with cam follower 106. This will actuate air valve so that air pressure is delivered to conduit 104. Piston will now move to release the detents 84 and spool 40 will returnto the neutral position. The flow of hydraulic fluid to the ram 20 will terminate and the bucket 16 will be stopped in the level position. When the boom arms 12 reach their lowermost position the bucket 16 will therefore be automatically positioned for the next digging operation. When the operator extends ram 20 further to move the bucket from the level to the carry position, cam 98 will function to close valve 100 so that the piston 110 will be inactivated.

It will be understood that various changes in the details, steps and arrangement of parts, which have been described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claim.

What I claim is:

In an automatic leveling device for a material handling bucket operated between level, carry, and dump positions by means of a hydraulic ram, the combination including: a bucket position indicator assembly mounted on the ram, the assembly including a drum having bucket position indicia thereon and being rotatably mounted on the head end of the ram and means to rotate the drum in response to extension and retraction of the ram; a camming surface on the drum; a cam follower in operating contact with the camming surface; first valve means selectively operable to direct hydraulic fluid to the ram for pivoting the bucket between the level, carry and dump positions; a source of air pressure; air operated motor means to neutralize the first valve means and terminate pivoting of the bucket; and second valve means in operating relationship with the cam follower to connect the source of air pressure with the motor means for operation thereof when the bucket reaches the level position.

References Cited by the Examiner UNITED STATES PATENTS HUGO O. SCHULZ, Primary Examiner. 

